September 9, 2011
At 35-37 Weeks, Babies Distinguish Pain From Touch
Researchers using electroencephalography (EEG) recorded the brain activity of preemies in response to pain, comparing their pain responses from a touch or prick on the heels. The premature children responded to pain around a woman´s 35th week of pregnancy, about two to four weeks before delivery, according to a new study from University College London.Dr. Rebeccah Slater, UCL Neuroscience, Physiology and Pharmacology, explained in a press release: “Premature babies who are younger than 35 weeks have similar brain responses when they experience touch or pain.”
“After this time there is a gradual change, rather than a sudden shift, when the brain starts to process the two types of stimuli in a distinct manner,” ABC News is reporting.
Children at more than 35 weeks´ gestation had a greater burst of activity in response to the lance than the simple touch. However babies, who were only 28 to 35 weeks in the womb showed the same brain activity for the touch and the heel lance.
These findings may explain why babies born prematurely have an abnormal sense of pain, and the findings could potentially affect treatment and care of preemies.
“Clinical practice changed about two decades or more ago to take into account the pain response of premature infants, and term infants,” Dr. Eliot Krane, a professor of anesthesia and pediatrics at Stanford University School of Medicine, told ABC's GMA reporter Mikaela Conley. “Clinical practice continues to evolve as we become more cognizant of the deleterious effect of pain in infants.”
Fetal pain, an area that experts say is lacking in research because it is difficult to study, has often been a point of tension in the ever-controversial abortion debate. Over the past six years, six states have enacted fetal pain abortion bans in which it is illegal to perform an abortion after 20 weeks.
Many anti-abortion rights activists argue that fetuses can feel pain in the womb after 20 weeks of development. “The findings ... should help inform the pain perception portion of the abortion debate,” Dr. F. Sessions Cole, director of the division of newborn medicine at Washington University School of Medicine at St. Louis, told ABC's Conley.
“Although this study specifically addresses brain wave differences between premature and term infants, not fetuses, after [receiving] painful and tactile stimuli, it suggests that brain maturation required for fetal pain perception occurs in late pregnancy, more than 11 weeks after the legal limit for abortion in the United States.
“Although fetal pain perception is a complex phenomenon which we do not yet fully understand, this study raises the possibility that maternal pain relief during abortion may require administration of medications more than fetal pain relief,” Cole continued.
Results of teh study were published Spet. 8 in the Current Biology journal.
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